It is well known to use self-powered wheeled machines to pick up and move roadway barrier segments disposed end-to-end from one location or another. Some of these roadway barrier moving machines move along a string of roadway barrier segments, lift the string and transfer the string to another location through the use of a conveyor. One example of such a barrier transfer machine is manufactured by Lindsay Transportation Solutions, 180 River Road, Rio Vista, Calif. and made available under the Barrier Systems and Quick Change trademarks. Barrier transfer machines are steered and operated either solely by manual control or manual control in conjunction with infrastructure modifications such as above or below grade guide wires or magnetic tape.
As will be discussed in greater detail below, the system of this invention automatically guides a machine that picks up and places roadway barrier segments using global satellite positioning (GPS) and ultrasonic technologies. The machine is guided by both GPS signals and signals based on ultrasonic measurements from the existing barrier segments.
It is known, of course, to guide vehicles generally based on GPS sensing and also generally based on ultrasonic sensing of some type. Examples of such guidance systems are shown in the following prior art: U.S. Pat. No. 5,549,412, issued Aug. 27, 1996, U.S. Patent Application Pub. No. US 2010/0215433, published Aug. 26, 2010, U.S. Pat. No. 5,052,854, issued Oct. 1, 1991, U.S. Patent Application Pub. No. US 2010/0202829, published Aug. 12, 2010, U.S. Pat. No. 6,220,780, issued Apr. 24, 2001, U.S. Pat. No. 6,022,168, issued Feb. 8, 2000, U.S. Pat. No. 5,253,951, issued Oct. 19, 1993, French Patent No. R2782331A1, issued Feb. 18, 2000 and European Patent No. EP1319757A2, issued Jun. 18, 2003.